Digital images are commonly printed onto paper and other substrates such as fabrics. In the printing industry, the quality of a printed image on a product depends on several factors. Some factors, such as substantive content and resolution of the digital image depend on the particular image itself. Others, such as the type and the color of the substrate on which the image is to be printed, affect the appearance of the image on the printed product. For example, textile substrates (i.e., fabrics) are known to absorb the ink, often resulting in visible fabric weave patterns in the printed image. The fabric therefore often acts as a physical filter which gives the appearance of having actually decreased the resolution from a higher-resolution original image.
Still other factors, such as the type, quality, and opacity of the ink, affect the appearance of the printed image. For example, colored inks (cyan, magenta, yellow, and black) are typically not fully (i.e., 100%) opaque, and colors of the image that have high contrast with the color of the substrate on which they are printed often appear faded. To remedy this problem, printers often first print a layer of fully opaque white ink over the entire area of the surface of the substrate that the image is to be printed on prior to printing the image itself. However, while this solution remedies the luminosity problems in the lighter colors of the printed image, it can present problems with the darker colors. Because the darker colors are generally not fully opaque, they can appear faded when printed over the white ink under-print layer. In addition, when printed on some substrates such as fabric, some of the white ink may even show completely through the dark ink, causing the resulting dark areas to appear faded and/or grainy.
In the field of printing designs onto apparel, some printing systems are particularly adapted to printing designs on dark materials. As described above, these systems typically first print a layer of white ink and then print the design on top of the white ink layer. This may result in better color reproduction of the design, but especially images with a higher percentage of lighter colors, using such a system is more expensive to purchase and operate. The system itself contains additional white ink printing components, additional white ink is required, the printing process is slower because of the extra printing steps, and the drying time is longer because of the additional ink that is applied.
There is, therefore, a need for systems and methods that improve the quality of a printed image.